The invention is based on a laser beam source for projecting laser pulses, in particular for machining material.
Such laser beam sources, embodied for instance as flash lamp- or diode-pumped solid-state lasers, are used among other purposes in machining material, for instance for welding, drilling or cutting (H. Hügel, “Strahlwerkzeug Laser”, Teubner-Verlag, Stuttgart, 1992). In it, a controllable shutter following the laser beam source and used for protection purposes is synchronized with the control of the pump device in such a way that first the shutter opens, and then the pulse-controlled flash lamps or diodes excite (pump) the laser-active medium, which in the case of the solid-state laser is the laser crystal. This sequence is maintained in order to prevent the closed shutter from being burned by the laser pulses, but as a consequence of it, in the first laser pulses projected after the activation of the pump device there are fluctuations in the pulse energy, which are caused by the thermal transient-response process of the laser-active medium. These fluctuations in energy have a very adverse effect on the machining process, especially in single-pulse machining, for instance in welding or drilling.